316 PROCEEDINGS OF THE AMERICAN ACADEMY. 



a ray and envelops the ray-achene by its thin infolded usually ciliate alar 

 portions. The achenes are glabrous and crowned with a shallow callous 

 cup, but otherwise pappusless. 



Although thus clearly marked, the species of this genus have from 

 habital similarities been much confused with those of Sabazia, Gallnsoga, 

 Melampodium, and Spilanthes. The following synopsis, drawn up during 

 the study of the two new species here proposed, may therefore be found 

 useful in showing the present status of the group. 



» Heads axillary, pedunculate, racemose, relatively large (including the rays 1.6 

 to 2 cm. in diameter) : rays about 12, conspicuous, pale yellow with more or 

 less deep roseate tinge: scales of the involucre ciliolate, otherwise glabrous: 

 weak aquatic essentially glabrous perennials. 



-t- Leaves slender-petioled. 



1. J. petiolaris. Sabazia glabra, Wats. Proc. Am. Acad, xxiii. 277. 

 — Shallow water, pine plains, base of the Sierra Madre, Pringle, no. 

 1295. The involute involucral scales enveloping the ray achenes clearly 

 show this plant a Jaegeria. The transfer of Dr. Watson's name glabra 

 to Jaegeria is rendered undesirable by the varietal use of this designation 

 under J. hirta by Mr. Baker in the Flora Brasiliensis as mentioned 



below. 



1- ■<- Leaves sessile, amplexicaul. 



2. J. purpurascens. Decumbent stem simple or sparingly branched, 

 purplish, glabrous, leafy : leaves oblong-lanceolate, acute, sessile by a 

 clasping base, entire, glabrous, 1.4 to 2 cm. long, 3 to 4 mm. wide: pe- 

 duncles terete, purplish, 3 to 4.2 cm. long, puberulent near the summit, 

 borne in the upper axils : disk 8 mm. in diameter, hemisiDherical, at 

 length somewhat conical: rays 11 to 13, linear or narrowly oblong, 

 purple, 6 mm. long : bracts of the open Hattish involucre uniseriate, ovate, 

 acute, strongly ciliate at the broadest involute part, green and glabrous 

 dorsally : disk-ilowers numerous ; corollas pale yellow, 2 mm. long, gla- 

 brous except for a tomentulose ring at the base of the tube : achenes 

 glabrous, 1.7 mm. long, crowned with a narrow callous ring otherwise 

 calvous : ligules pale-yellow, shading to deep purple at the tip, 5 mm. 

 lono-, 1.8 mm. broad. — Collected in shallow water near Durango, Mex- 

 ico, by Dr. Edward Palmer, November, 1896, no. 805 (distributed as 

 Sabazia glabra). 



* * Heads solitary and axillary (.7. prorepens) or more often terminal in the forks 

 of the stem, or, when several, borne in leafy cymes : more or less pubescent 

 plants of muddy shores or drier habitat : rays yellow or white. 



